The Potential Prognostic Marker TyG Index Predicts Time to Brain Metastasis at HER2 Positive Breast Cancer

Ibrahim Karadag,1 Serdar Karakaya,2 Tolga Akkan,3 Bilgin Demir,4 Ertugrul Gazi Alkurt,5 Mutlu Dogan6 1Department of Medical Oncology, Hitit University Erol Olcok Training and Research Hospital, Corum, Turkey; 2Department of Medical Oncology, Health Science University, Atatürk Chest Diseases and Chest Surgery Training and Research Hospital, Ankara, Turkey; 3Department of Endocrinology, Eskisehir City Hospital, Eskisehir, Turkey; 4Department of Medical Oncology, Ayd&inodot;n Atatürk Public Hospital, Ayd&inodot;n, Turkey; 5Department of Surgical Oncology, Hitit University Erol Olcok Training and Research Hospital, Corum, Turkey; 6Department of Medical Oncology, Health Sciences University, Ankara Dr. Abdurrahman Yurtaslan Oncology Training and Research Hospital, Ankara, TurkeyCorrespondence: Ibrahim Karadag, Email ikaradag58@gmail.comBackground: We aimed to investigate the prognostic significance of insulin resistance (IR) markers fasting triglyceride-glucose (TyG) index and triglyceride high-density lipoprotein cholesterol (TG/HDL-C) ratio in HER2-positive breast cancer (BC) patients with brain metastasis (BM).Methods: In this single-center study, 120 patients who met the criteria were included. TyG and TG/HDL-C at the time of diagnosis were computed retrospectively. For TyG and TG/HDL-C, the median values of 9.32 and 2.95 were taken as the cut-off, respectively. TyG values < 9.32 and < 2.95 were considered low, and TG/HDL-C values ≥ 9.32 and ≥ 2.95 were considered high.Results: The median overall survival (OS) was 47 months (95% CI: 40.54– 53.45). Time to BM was 22 months (95% CI: 17.22– 26.73). The median time to BM was 35 months (95% CI: 20.90– 49.09) in the low TyG group and 15 months (95% CI: 8.92– 21.07) in the high TyG group (p < 0.001). The time to BM was 27 months (95% CI: 20.49– 33.50) in the low TG/HDL-C group and 20 months (95% CI: 16.76– 23.23) in the high TG/HDL-C group (p=0.084). In the multivariate Cox regression analysis, the TyG index (HR: 20.98, 95% CI: 7.14– 61.59, p < 0.001) was an independent risk factor for time to BM.Conclusion: These findings suggest that the TyG index could be used as a predictive biomarker at the time of diagnosis for risk of time BM in patients with HER2-positive BC. The TyG index can be used as a standard potential marker with prospective studies confirming these data.Keywords: TyG index, TG/HDL-C ratio, brain metastasis, HER2 positive breast cancer, glucose-lipid metabolism